Apparatus for injection molding

Abstract

The injection molding machine has an extruder for providing molding material, a cavity for retaining the molding material prior to injection into a mold, a plunger within the cavity to move the material out of the cavity, and a check valve. The check valve has separate means to permit the material to flow from the extruder to the cavity and from the cavity to an adjacent mold. By having separate flow channels for molding and recharging, the injection molding machine may be recharged on the fly.

What is claimed is:  
     
       1. An apparatus for injection molding material into a mold, the apparatus comprising an extruder for providing molding material, a cavity for retaining the molding material prior to injection into a mold, a plunger within the cavity to move the material out of the cavity, a check valve, the check valve being characterized by: 
       the check valve comprising separate means to permit the material to flow from the extruder to the cavity and from the cavity to a mold;  
       the check valve having an external shape that inhibits rotation and misalignment of the check valve.  
     
     
       2. An apparatus in accordance with  claim 1  wherein the check valve is activated by a hydraulic cylinder. 
     
     
       3. An apparatus in accordance with  claim 1  wherein the check valve is block shaped. 
     
     
       4. An apparatus in accordance with  claim 1  wherein the check valve moves axially along its centerline to move the valve from an injecting position to a recharging position. 
     
     
       5. An apparatus in accordance with  claim 1  wherein the check valve has a radial cross-section configuration selected from the following group of circular, oval, triangular, and polygonal. 
     
     
       6. An apparatus for injection molding material into a mold, the apparatus comprising an extruder for providing molding material, an apparatus cavity having an access port for receiving the molding material prior to injection into a mold, a plunger within the cavity to move the material out of the apparatus cavity, a check valve, the check valve being characterized by: 
       (a) an internal transfer column cavity moving axially along a check valve centerline relative to the apparatus cavity access port;  
       (b) an entrance port communicating with the transfer column cavity and allowing passage of the molding material from the extruder to the transfer column cavity;  
       (c) an exit port communicating with the transfer column cavity and allowing passage of the molding material from the transfer column cavity into the apparatus cavity; and  
       (d) an injection outlet port for allowing passage of the molding material from the apparatus cavity through the check valve.  
     
     
       7. An apparatus in accordance with  claim 6  wherein the check valve moves axially along its centerline to move the valve from an injecting position to a recharging position, the valve entrance port and the valve exit port being closed in the injecting position and open in the recharging position, and the valve injection outlet port being open in the injecting position and closed in the recharging position. 
     
     
       8. An apparatus in accordance with  claim 7  wherein the check valve moves reciprocally along its centerline between the injecting position to the recharging position to alternatively open and close the entrance port, the exit port, and the injection outlet port. 
     
     
       9. An apparatus in accordance with  claim 7  wherein the check valve transfer column is transversely oriented relative to the apparatus cavity. 
     
     
       10. An apparatus in accordance with  claim 6  wherein the injection outlet port extends transversely through the check valve relative to the check valve centerline.